1. Field of Endeavor
The present invention relates to detection systems and more particularly to a detection system using high gamma ray signature to detect contraband special nuclear materials in cargo.
2. State of Technology
U.S. Pat. No. 6,344,818 to Yuri Markov Feb. 5, 2002 for apparatus and method for the detection of materials provides the following state of technology information, “The ability to detect the presence of a material in any location is a requirement in many disciplines and industries. Determining if a particular material in large or small quantities is present at any location is a concern in medicine, research, exploration forensics, security, law enforcement, and for safety reasons. For example, at points of entry for national borders, and at some complexes, and buildings it can be necessary that contents of baggage and boxes and other such cargo containers be identifiable by inspection or detection methods when searching for contraband such as narcotics, stolen goods, unauthorized medicines and plants explosives and accelerants, liquids, chemicals, and other materials.”
U.S. Pat. No. 6,347,132 to Martin Annis issued Feb. 12, 2002 for an x-ray inspection system for automatically detecting nuclear weapons materials provides the following state of technology information, “The detection of contraband (e.g., explosives and drugs) in closed containers is of growing importance worldwide. World events have necessitated tighter screening requirements for the contents of containers placed on aircraft to detect the presence of explosives. In addition, to combat the illegal flow of narcotics across national borders, the contents of containers, such as loaded trucks and vehicles must be inspected to check for the presence of narcotics. High energy x-ray inspection systems remain one of the only technologies capable of inspecting loaded cargo containers and vehicles. There is also a need to inspect containers for nuclear grade weapons' materials. There is a growing concern that some of these materials may come into possession of terrorists, due to the relatively large volume of nuclear weapons grade materials stored worldwide. Detectors such as Geiger counters and gamma ray detectors are well known for detecting nuclear weapons materials. However, since Uranium does not emit a significant flux of gamma rays, it can not be detected by a gamma ray detector (e.g., a gamma ray detector mounted outside of the truck which contains the contraband).”